A maple syrup extract alleviates liver injury in type 2 diabetic model mice.

A recent study showed that 54% of type 2 diabetes (T2D) patients have nonalcoholic fatty liver disease, which is a risk factor for aggravation diabetic symptoms. Previous studies suggested components in maple syrup alleviated liver injury and found polyphenols as food components to improve the symptoms and complications of diabetes. Therefore, we hypothesized that a polyphenol fraction in maple syrup improves the symptoms and complications of diabetes. To address the hypothesis, we investigated the effects of a polyphenol-rich maple syrup extract (MSE) on a T2D model mice. KK-Ay mice were fed a normal or 0.1% MSE-supplemented diet for 43 days. The results showed that the levels of serum alanine aminotransferase and aspartate aminotransferase were significantly reduced in mice that ingested MSE. Hepatic genes related to lipogenesis and lipolysis were down- and upregulated, respectively, in mice that ingested MSE. These results suggest that MSE intake alleviates liver injury and suppresses lipid accumulation in the livers of T2D mice.

Oral Administration of Edible Seaweed Undaria Pinnatifida (Wakame) Modifies Glucose and Lipid Metabolism in Rats: A DNA Microarray Analysis.

SCOPE: Wakame is an edible seaweed that is a common constituent in the Japanese diet. Previous studies showed that wakame consumption is associated with the prevention of metabolic syndrome, but the molecular mechanisms underlying the protective effects are poorly understood. METHODS AND RESULTS: To determine if the expression of hepatic genes is affected by ingestion of the brown seaweed Undaria pinnatifida (wakame), rats were fed a diet containing 0, 0.1, or 1.0 g per 100 g dried wakame powder for 28 days. Administration of 1% wakame significantly decreased serum total cholesterol levels. Hepatic gene expression was investigated using DNA microarray analysis, and the results showed that wakame suppresses the lipogenic pathway by downregulating SREBF-1. Moreover, bile acid biosynthesis and gluconeogenesis were promoted by upregulation of the PPAR signaling pathway, which leads to a reduction in the accumulation of cholesterol and promotion of ß-oxidation. CONCLUSIONS: These results suggest that wakame ingestion affects glucose and lipid metabolism by altering the expression of SREBF-1 and PPAR signal-related genes.

Overexpression of KCNJ2 in induced pluripotent stem cell-derived cardiomyocytes for the assessment of QT-prolonging drugs.

Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes hold great potentials to predict pro-arrhythmic risks in preclinical cardiac safety screening, although the hiPSC cardiomyocytes exhibit rather immature functional and structural characteristics, including spontaneous activity. Our physiological characterization and mathematical simulation showed that low expression of the inward-rectifier potassium (IK1) channel is a determinant of spontaneous activity. To understand impact of the low IK1 expression on the pharmacological properties, we tested if transduction of hiPSC-derived cardiomyocytes with KCNJ2, which encodes the IK1 channel, alters pharmacological response to cardiac repolarization processes. The transduction of KCNJ2 resulted in quiescent hiPSC-derived cardiomyocytes, which need pacing to elicit action potentials. Significant prolongation of paced action potential duration in KCNJ2-transduced hiPSC-derived cardiomyocytes was stably measured at 0.1 µM E-4031, although the same concentration of E-4031 ablated firing of non-treated hiPSC-derived cardiomyocytes. These results in single cells were confirmed by mathematical simulations. Using the hiPSC-derived cardiac sheets with KCNJ2-transduction, we also investigated effects of a range of drugs on field potential duration recorded at 1 Hz. The KCNJ2 overexpression in hiPSC-derived cardiomyocytes may contribute to evaluate a part of QT-prolonging drugs at toxicological concentrations with high accuracy.

Collagen peptide ingestion alters lipid metabolism-related gene expression and the unfolded protein response in mouse liver.

Ingestion of collagen peptide (CP) elicits beneficial effects on the body, including improvement in blood lipid profiles, but the underlying mechanisms remain unclear. The purpose of this study was to investigate the effects of CP ingestion on the liver, which controls lipid metabolism in the body. Male BALB/cCrSlc mice were bred with the AIN-93M diet containing 14 % casein or the AIN-93M-based low-protein diet containing 10 % casein or a diet containing 6 % casein+4 % CP for 10 weeks (n 12/group). Total, free and esterified cholesterol levels in the blood decreased in the CP group. DNA microarray analysis of the liver revealed that expressions of genes related to lipid metabolic processes such as the PPAR signalling pathway and fatty acid metabolism increased in the CP group compared with the 10 % casein group. The expressions of several genes involved in steroid metabolic process, including Cyp7a1 and Cyp8b1, were decreased, despite being targets of transcriptional regulation by PPAR. These data suggest that lipid metabolism in the liver is altered by CP ingestion, and the decrease in blood cholesterol levels in the CP group is not due to enhancement of the steroid metabolic process. On the other hand, expressions of genes related to the unfolded protein response (UPR) significantly decreased at the mRNA level, suggesting that CP ingestion lowers endoplasmic reticulum stress. Indeed, protein levels of phosphorylated inositol-requiring enzyme 1 decreased after CP ingestion. Taken together, CP affects the broader pathways in the liver - not only lipid metabolism but also UPR.

A High Phosphorus Diet Affects Lipid Metabolism in Rat Liver: A DNA Microarray Analysis.

A high phosphorus (HP) diet causes disorders of renal function, bone metabolism, and vascular function. We previously demonstrated that DNA microarray analysis is an appropriate method to comprehensively evaluate the effects of a HP diet on kidney dysfunction such as calcification, fibrillization, and inflammation. We reported that type IIb sodium-dependent phosphate transporter is significantly up-regulated in this context. In the present study, we performed DNA microarray analysis to investigate the effects of a HP diet on the liver, which plays a pivotal role in energy metabolism. DNA microarray analysis was performed with total RNA isolated from the livers of rats fed a control diet (containing 0.3% phosphorus) or a HP diet (containing 1.2% phosphorus). Gene Ontology analysis of differentially expressed genes (DEGs) revealed that the HP diet induced down-regulation of genes involved in hepatic amino acid catabolism and lipogenesis, while genes related to fatty acid ß-oxidation process were up-regulated. Although genes related to fatty acid biosynthesis were down-regulated in HP diet-fed rats, genes important for the elongation and desaturation reactions of omega-3 and -6 fatty acids were up-regulated. Concentrations of hepatic arachidonic acid and eicosapentaenoic acid were increased in HP diet-fed rats. These essential fatty acids activate peroxisome proliferator-activated receptor alpha (PPARα), a transcription factor for fatty acid ß-oxidation. Evaluation of the upstream regulators of DEGs using Ingenuity Pathway Analysis indicated that PPARα was activated in the livers of HP diet-fed rats. Furthermore, the serum concentration of fibroblast growth factor 21, a hormone secreted from the liver that promotes fatty acid utilization in adipose tissue as a PPARα target gene, was higher (p = 0.054) in HP diet-fed rats than in control diet-fed rats. These data suggest that a HP diet enhances energy expenditure through the utilization of free fatty acids released via lipolysis of white adipose tissue.

Broccoli sprout extract induces detoxification-related gene expression and attenuates acute liver injury.

AIM: To investigate the effects of broccoli sprout extract (BSEx) on liver gene expression and acute liver injury in the rat. METHODS: First, the effects of BSEx on liver gene expression were examined. Male rats were divided into two groups. The Control group was fed the AIN-76 diet, and the BSEx group was fed the AIN-76 diet containing BSEx. After a 10-d feeding period, rats were sacrificed and their livers were used for DNA microarray and real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses. Next, the effects of BSEx on acute liver injury were examined. In experiments using acute liver injury models, 1000 mg/kg acetaminophen (APAP) or 350 mg/kg D-galactosamine (D-GalN) was used to induce injury. These male rats were divided into four groups: Control, BSEx, Inducer (APAP or D-GalN), and Inducer+BSEx. The feeding regimens were identical for the two analyses. Twenty-four hours following APAP administration via p.o. or D-GalN administration via i.p., rats were sacrificed to determine serum aspartate transaminase (AST) and alanine transaminase (ALT) levels, hepatic glutathione (GSH) and thiobarbituric acid-reactive substances accumulation and glutathione-S-transferase (GST) activity. RESULTS: Microarray and real-time RT-PCR analyses revealed that BSEx upregulated the expression of genes related to detoxification and glutathione synthesis in normal rat liver. The levels of AST (70.91 ± 15.74 IU/mL vs 5614.41 ± 1997.83 IU/mL, P < 0.05) and ALT (11.78 ± 2.08 IU/mL vs 1297.71 ± 447.33 IU/mL, P < 0.05) were significantly suppressed in the APAP + BSEx group compared with the APAP group. The level of GSH (2.61 ± 0.75 nmol/g tissue vs 1.66 ± 0.59 nmol/g tissue, P < 0.05) and liver GST activity (93.19 ± 16.55 U/g tissue vs 51.90 ± 16.85 U/g tissue, P < 0.05) were significantly increased in the APAP + BSEx group compared with the APAP group. AST (4820.05 ± 3094.93 IU/mL vs 12465.63 ± 3223.97 IU/mL, P < 0.05) and ALT (1808.95 ± 1014.04 IU/mL vs 3936.46 ± 777.52 IU/mL, P < 0.05) levels were significantly suppressed in the D-GalN + BSEx group compared with the D-GalN group, but the levels of AST and ALT in the D-GalN + BSEx group were higher than those in the APAP + BSEx group. The level of GST activity was significantly increased in the D-GalN + BSEx group compared with the D-GalN group (98.04 ± 15.75 U/g tissue vs 53.15 ± 8.14 U/g tissue, P < 0.05). CONCLUSION: We demonstrated that BSEx protected the liver from various types of xenobiotic substances through induction of detoxification enzymes and glutathione synthesis.

Oral administration of the AYA strain of Lactobacillus plantarum modulates expression of immunity-related genes in the murine Peyer's patch: a DNA microarray analysis.

We performed comprehensive transcriptome analysis of Peyer's patches to elucidate the effects of oral administration of Lactobacillus plantarum strain AYA in mice. Using microarray analysis, we identified 124 upregulated and 144 downregulated genes for four weeks after the start of dietary supplementation with AYA. Gene Ontology analysis revealed that the genes for immune function were enriched in the upregulated gene set.

Administered chrysanthemum flower oil attenuates hyperuricemia: mechanism of action as revealed by DNA microarray analysis.

We applied Chrysanthemum flower oil (CFO) to a hyperuricemia model by feeding rats a hyperuricemia-inducing diet (HID) and investigated its effect on serum uric acid (SUA) levels and its mode of action. CFO is the oily fraction that contains polyphenols derived from chrysanthemum flowers. Oral administration of CFO to HID-fed rats significantly decreased their SUA levels. It also inhibited xanthine oxidase activities in the liver and increased urine uric acid levels. The effects of CFO on the renal gene expressions that accompanied the induction of hyperuricemia were comprehensively confirmed by DNA microarray analysis. The analysis showed up-regulation of those genes for uric acid excretion by CFO administration. These results suggest that CFO suppresses the increase in SUA levels via two mechanisms: suppression of uric acid production by inhibition of xanthine oxidase in the liver and acceleration of its excretion by up-regulation of uric acid transporter genes in the kidney.

High phosphorus diet-induced changes in NaPi-IIb phosphate transporter expression in the rat kidney: DNA microarray analysis.

The mechanism by which phosphorus levels are maintained in the body was investigated by analyzing changes in gene expression in the rat kidney following administration of a high phosphorus (HP) diet. Male Wistar rats were divided into two groups and fed a diet containing 0.3% (control) or 1.2% (HP) phosphorous for 24 days. Phosphorous retention was not significantly increased in HP rats, but fractional excretion of phosphorus was significantly increased in the HP group compared to controls, with an excessive amount of the ingested phosphorus being passed through the body. DNA microarray analysis of kidney tissue from both groups revealed changes in gene expression profile induced by a HP diet. Among the genes that were upregulated, Gene Ontology (GO) terms related to ossification, collagen fibril organization, and inflammation and immune response were significantly enriched. In particular, there was significant upregulation of type IIb sodium-dependent phosphate transporter (NaPi-IIb) in the HP rat kidney compared to control rats. This upregulation was confirmed by in situ hybridization. Distinct signals for NaPi-IIb in both the cortex and medulla of the kidney were apparent in the HP group, while the corresponding signals were much weaker in the control group. Immunohistochemical analysis showed that NaPi-IIb localized to the basolateral side of kidney epithelial cells surrounding the urinary duct in HP rats but not in control animals. These data suggest that NaPi-IIb is upregulated in the kidney in response to the active excretion of phosphate in HP diet-fed rats.

Effect of oral intake of winged bean extract on a skin lichenification model: evaluation by microarray analysis.

Winged bean (WB), Psophocarpus tetragonolobus, is a tropical legume, the potential of which is not fully understood. We found that 5-week oral administration of a WB seed extract inhibited wrinkle formation induced by repeated tape stripping (TS) as a model of lichenification in human chronic eczematous dermatitis. To elucidate the mechanism of the effect of WB on this model, we applied microarray analysis. Hierarchical clustering revealed that each experimental group formed a distinct cluster, suggesting the presence of a distinct gene expression profile among the three groups of non-TS, TS, and TS with oral administration of WB extract (TS/WB). Gene ontology analysis showed that several gene groups with keratinization and mitosis were significantly upregulated by TS, while other groups with ATP synthesis and glycolysis were significantly downregulated by TS/WB. Moreover, WB extract influenced a number of genes related to epidermal differentiation and inflammation. This suggests that these changes inhibited wrinkle formation by TS.

Hepatic gene expression of the insulin signaling pathway is altered by administration of persimmon peel extract: a DNA microarray study using type 2 diabetic Goto-Kakizaki rats.

Persimmon (Diospyros kaki) is a very popular fruit in East Asian countries, but its peels are not consumed despite the fact that they contain many antioxidants such as carotenoids and polyphenols. We prepared a fat-soluble extract from persimmon peel (PP) and fed type 2 diabetic Goto-Kakizaki (GK) rats an AIN-93G rodent diet supplemented with persimmon peel extract (PP diet) for 12 weeks. Compared with the control AIN-93G diet, the PP diet significantly reduced plasma glutamic-pyruvate transaminase activity, with accumulation of ß-cryptoxanthin in the liver. DNA microarray analysis revealed that the PP diet altered hepatic gene expression profiles. In particular, expression of insulin signaling pathway-related genes was significantly enriched in differentially expressed gene sets. Moreover, Western blotting analysis showed an increase in insulin receptor beta tyrosine phosphorylation in rats fed the PP diet. These data suggest that the PP diet improves insulin resistance in GK rats.

Neuron differentiation-related genes are up-regulated in the hypothalamus of odorant-inhaling rats subjected to acute restraint stress.

To elucidate some physiopsychological effects of a pleasant odor, we analyzed gene expression profiles in the hypothalamus of rats which, under a restraint-stressed condition, inhaled (R)-(-)-linalool. Consequently, 697 probe sets showed significant expression changes in the odorant-inhaling rats subjected to 2 h of restraint stress (false discovery rate < 0.05). We observed up-regulation of 594 among them, including genes related to neuron differentiation and transcriptional regulatory factors. Another important result was that inhalation of (R)-(-)-linalool returned the expression of 49 restraint-regulated genes to a normal condition. In contrast, the inhalation also further up-regulated the expression of 16 restraint-up-regulated genes that included those encoding heat shock proteins as factors to induce some biological responses against stresses. In the present study we thus found the substantial example that, in the hypothalamus involved in feeding behaviors, an inhaled pleasant odor acts to regulate the gene expression related to the functions of neuronal developments to cope with stresses.